Transmission control apparatus



y 1952 B. FORMAN 2,603,037

TRANSMISSION CONTROL APPARATUS Filed Jan. 21, 1949 s Sheets-Sheei 1 34 I INVENTOR.

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- A EB- y 1952 1.. B. FORMAN 2,603,037

TRANSMISSION CONTROL APPARATUS FiledfJan. 21, 1949 5 Sheets-Sheet 5 INVENTOR. jozzz'sflfi f'ormarz BY MMJW J IOFIVZY Patented July 15, 1 952 Louis B. Forman, Detroit, 'Mich., 'assign'or to Chrysler Corporation, Highland Park, Mich., a

corporation of Delaware Application January 21, 1949, Serial No. 71,933

This invention relates to a transmission control mechanism for an automotive vehicle and more particularly to means to control the initiation of a change in transmission speed ratio drive.

Reference will be made herein to a relatively fast speed drive which is usually the cruising drive for a vehicle. This may, for example, be a one to one driving speed ratio known as a direct drive or an overdrive. Reference will also be made to a relatively slow speedv drive which is a vehicle accelerating speed ratio drive and may be a torque multiplying drive, or where an overdrive is provided for the relatively fast speed drive the relatively slow speed drive maybe a direct drive. The term kiclrdo'wn, as used herein, refers to a downshift or step-down in the transmission as, for example, a downshift from the relatively fast speed drlveto the relatively slow speed drive.

In automotive vehicles having automatic controls associated with variable speed ratio transmissions it has been found desirable to provide means responsive to control by the operator for reverting to a relatively slow speed drive when the operator is confronted with an emergency demanding fast acceleration. Such means have usually included a solenoid actuator and controls therefore including a switch which is arranged to cooperate with the engine carburetor throttle control mechanism so as to cause a change in speed ratio drive of the vehicle when the usual accelerator pedal is depressed to a predetermined position. It has also been found with such arrangements that under certain conditions as where the vehicle is travelingat a comparatively high rate of speed the transmission cannot be safely operated'in a relatively slow speed drive as above described due to the excessive engine speed which would be required. Means have heretofore been provided'for limiting the operation of such controls to those engine and vehicle speeds inwhich a relatively slow speed drive may be safely accommodated.

It is an object of this inventionto provide a control for a variable speed ratio transmission ioia'ims. (01. 47-472) by means of which a solenoid actuator associated with the transmission may be actuated'to effect'a change ln transmission-speed ratio drive by'positioning the throttle control linkage in "a predetermined position and to assooiatewith this control a means to maintain the condition of the control soestabllshed after the throttle control linkage has retracted from the. above predetermined position. The speed ratio drive effected by the solenold is' thus ninntamedsnsrtne' throttle 4 v2 control linkage has-been moved fromthe above predetermined position.

It is an additional object of this invention to associate the above control with a second control adapted to render; the first control inoperative above a predetermined vehicle'speed.

The transmissions illustrated and described in Patent No. 2,348,763 issued on May 1 1 -4 J. Syrovy et al. and the copending application, Serial No. 374,674, of 'Neracher et al., are examples of transmissions to which the controls to be described herein may be applied.

In the drawings:

Fig. 1 is a diagrammatic view showing a portion of an automotive engine including a carburetor and a power transmission with the present invention applied thereto;

Fig. 2'isan enlarged sectional view illustrating the control mechanism applied to the carburetor shown in Fig. 1, a portion of the carburetor being broken away;

Fig. 3 isaside elevation, of the carburetor and control of Fig. 1; v

Fig. 4 isa partial elevation of the devlceillustrated in Fig. 3;

Fi .5 isa side elevation of a carburetor embodying amodified form of the invention;

Fig. 6 is a partial elevation of the device illustrated inFig. 5;

Fig. 71s an enlarged view, partly in section, of a portion of the control mechanism of Fig. '5;

Fig. 8 is a side elevationof a carburetor embodying I another form of .the invention Fig. Qis :a partial elevation o'ithe device illustrated'in Fig. '8;

Fig. 10 is an enlarged view, partly in section, of a'p'ortion of the control mechanism ofFig. 5; and I Fig.1-1 is a view,.part1y insection, of a modified form of a switch control-mechanism.

Certain ."abb'rev'iated terminology will be adopted herein to facilitate the description of the invention. lTh'e means "associated with the throttle controllinkage and whioh'ls adapted to eaus'e a relativelysl'ow speed drive "to be effected will be hereinafter'relerred'to as a meltdown control. Thel'n'e'a ns which llmitstheoperation of the "klckdown control to "certain engine and vehicle speeds will bereferredit'oas an upper limit control.

Itisfappa'rent thatthe control desired herein should be assocla'tediwith'some manipulation of the"thro'ttle linkage which will signal the operatorsde'sire for an'upsliift" and yet permit some latitude "of vehicle operatlon with respect to engine speed during the relatively slow speed drive. The control, therefore, should be designed to initiate an upshift as the throttle is brought towards a throttle closing position beyond the lower limit of throttle opening that would normally be desired in the operation of the vehicle in its relatively slow speed drive.

The numeral Ill generally indicates an internal combustion engine having an intake manifold l2 on which is mounted a carburetor l4. The carburetor is provided with a conventional throttle valve [5 (Fig. 3) which is adapted to be manipulated by movement of an accelerator pedal [6. The pedal 16 is yieldably urged to its throttle closing position by a spring 18. Pedal [6 which is pivotally mounted at 20 has linkage operatively connected thereto for remote control of the throttle and this linkage is indicated by the numerals 22, 24, 26, 28 and shaft 30.

A variable speed ratio transmission has been generally indicated by the numeral '32 and is positioned rearwardly of the engine l and adapted to transmit drive from the engine It) to a propeller shaft (not shown). U. S. Patent No. 2,348,763 and copending application, Serial No. 374,674, illustrate transmissions which could be controlled by the apparatus to be described herein. A solenoid actuator 34 illustrated as mounted on the side of the transmission 32 may be associated with the transmission control apparatus so that energization of the solenoid actuator 34 will effect a kickdown or downshift of the transmission to a relatively slow speed drive. Deenergization of the solenoid actuator 34 may be utilized to effect an upshift of the transmission to a relatively fast speed drive.

In Fig. 1 a typical circuit with which my invention may be associated for the control of the energization of solenoid actuator 34 has been illustrated as including a vehicle storage battery 36 which is grounded at 38. The circuit from the battery includes a conductor 35 connecting the battery to the solenoid actuator 34, a conductor 3'1 connecting solenoid actuator 34 to a grounded vehicle speed responsive governor 43 having terminals 46 and 45 and switch mean 39 to electrically connect these terminals when the vehicle speed is less than a predetermined value. The circuit also includes a grounded kickdown control switch 42 incorporating my invention andconnected by a conductor 41 to the conductor 31 so that the governor switch 39 and kickdown switch 42 are in parallel. The switches 39 and. 42 are each operable when closed to ground the circuit. The governor 43 may be of any suitable design which is operatively connected to a driven portion of the transmission.

Operation of the kickdown control to be discussed herein is limited to those occasions on which the predetermined vehicle speed controlling the governor 43 has been exceeded so that the terminals 40 and 45 are not electrically connected. A kickdown control is not necessary below this predetermined speed as the governor switch 39 provides an energization of solenoid actuator 34 and a relatively slow speed drive.

The kickdown control switch 42 is illustrated in detail in Figure 2. An electrical conductor 4|, previously referred to, is connected with a first conductor terminal 44 which is electrically insulated at 46 from the supporting carburetor parts. A movable contacting conductor 43 of silver or other suitable material is connected to and extends downwardly froma piston 50. The conductor 48 is free from engagement with the first 4 terminal 44 prior to operation of the kickdown control mechanism as hereinafter described. Conductor 48 is sufliciently resilient so that it can be flexed into contact with the terminal 44 and will assume its Figure 2 position again when the parts are in position as shown.

The piston 50 which is the movable portion of the upper limit control previously referred to is free to slide in a cylinder 52 and is urged downwardly therein by a spring 54 until the piston engages the insulation 46. The upper end of the piston is open to receive the spring 54 and the interior of cylinder 30 is connected by a passage 56 to the engine intake conduit at the atmospheric side of the throttle valve so that the piston 50 is always subjected to the vacuum ex- 7 isting on the atmospheric side of the throttle valve. It is preferable if the passage 56 is connected to the throat of the conventional carburetor venturi (not shown).

The spring 54 yieldably urges the piston 55 downwardly to the position illustrated in Figure 2 to position the contact 43 in line with the fixed terminal 44 for engagement therewith under the influence of the control mechanism unless the vacuum in the intake and passage 56 is sufiicient to withdraw piston 50 and contact 48 upwardly out of alignment with the terminal 44.

Means are provided herein which are responsive to operation of the throttle control mechanism during a portion of its throttle opening movement and preferably during. that portion thereof when the accelerator pedal I6 is brought to its fully depressed position corresponding to approximately full open position of the throttle valve l5, or an overtravel of the pedal beyond the full open throttle valve position, to ground the conductor 44 through contact 48. A plungerlike member 60 is slidably mounted in a cylinder 62 formed in the housing of switch 42. A second plunger-like member 64 is slidably received in a bore 66 provided in member 60. The members 60 and 64 are retained against relative separation in an axial direction by an enlarged portion 68 of the member 64 cooperating with an inwardly directed flange 13 carried by the member 60. The members 60 and 64 are yieldably urged to their Figure 2 position by a relatively heavy spring 72 which reacts against a plate 14 carried by plunger 60, and the housing of switch 42. A spring I6 interposed directly between the members 63 and 64 urges the enlarged portion of the member 64 to the left as viewed in Figure 2 against the flange 16 of the member 60 and the members 63 and 64 as thus assembled cooperate to serve as a switch operating plunger device. The lever 28 which forms a part of the linkage connecting the accelerator pedal with the throttle valve, and which was previously referred to, is illustrated in Figure 3 as provided with an extension adapted to contact the exterior end of member 60 or its associated plate 14 when the pedal is depressed so that the throttle valve I5 is in substantially wide open throttle position. If desired, the contact of extension 80 with plate '14 may be adjusted to occur in response to an overtravel of the pedal l6 beyond full open throttle position. In either event the extension 83 applies an axial force tending to move the member 60 to the left in Fig. 2 in response to contact ofgthese parts. This movement occurs against the opposition of spring 12 and the plunger-like member 64 is yieldably forced to the left in Fig. 2 by spring 16 until it flexes the contact terminal 48 into contact with the terminal 44. The condoctor is thus grounded through 44,48, 64 and the parts within the bore 62 which are in electrical connection with-the carburetor casing.

When, however, the vacuum on the atmospheric side of the throttle valve is suiiicient to draw the piston 50 upwardly against the force of the spring 54 and thereby dispose thecontact 48 out of alignment with the terminal M depression of the accelerator pedal I6, as aforesaid, will not result in formation of the grounded electric circuit for'the parts are so arranged that the plunger like member 64 does not have sufiiheretofore employedin the art. However, in oer-- tain transmissionsit is desirable'to provide latching means for retaining the member 64, contact 48 and terminal 44 in electrical contact after the accelerator pedal It has initiated a kickdown and'subsequently been retracted to a more modiiied throttle opening position. Therefore, 1 have found it desirable to provide a pair'of spaced recesses BI and 82 on the periphery of member 60, a balldetent 84 and spring 83 adapted to extend the detentfor engagement selectively with the recesses BI and 82. The cooperation of the Force is applied in one direction by, contact of extension 80 of lever 28 with plate 14 or member 60. However, when the kickdown has beeneffected and the member 60 is so positioned that the ball detent'B4 is in engagement with the recess 8| then it becomes necessary to provide a supplemental means for applying a force to'move the member 60 to the right in Fig. 2 to disconnect the memberfid from contact 48 toreturn the vehicle to a higher speed ratio drive. For this purpose an extension 90 has been'provided on the lever 22. The extension 90 is so positioned with respect to the lever 28 and the plate 14 that a return of the pedal I6 and the associated throttle control linkage toward a closed throttle position will at a desired predetermined position I efiect an engagement of the "extension 90 with theplate I4 so that continued movement-f the linkage toward a throttle closingposition under the influence of spring. I8 will force the plate I4 and member 60 to the right in Fig. 2 into the position illustrated in Fig. 2'to effect a separation of member 64 from contact 48 and a deenerg'ization of solenoid actuator 34 with aconsequent upshiit in transmission speed ratio drive. It is assumed, of course, that the governor switch is open at this time because the vehicle speed exceeds the predetermined vehicle speed controlling the closing of the governor switch. It is only under these conditions that'an'operator would require the switch 42to induce'an upshiit.

Figs. 5, 6 and Tillustrate a modified form of latching means for the member 60. 'The spring pressed ball detent 84 and recesses BI and 82 are omitted'in this form of the invention and the spring 12 described in Fig. 2 is positioned within the circular bore -62. This spring is labelled I2 in Fig. 7. The member is designated by the numeral 60' in Fig. land is provided with a shoulder lflo'adapted to COOPerate with'ashoulder I02 onthe casing oithe switch 42 to limitthe axial movement .of the member.

60 under the infiuence'of the spring 12. The extension 80 'on throttle control linkage lever 28 is adapted to engage'the' endof member 60'- whenthe accelerator pedal I6 is depressed, as explained with reference to Figs. 1 and2, to effect a closing of the switch 42as explainedabove An inverted U-shaped rod I04has an extension I06 provided on one end thereof. One leg of the rod I04 is received in a vertical circularopening I08 in-the switch housing. The other leg of the rod I04 is carried by a bracket IIO mounted on switch 42 and has a spring'l I2 associated therewith. The spring II2 reacts between the bracket H0 and a collar II 4 provided on rod I04 to urge rod -I04 to move downwardly so that the extension I06 thereon can drop behind the shoulder I00 ofmember 60' to hold the switch in kickdown position when the member 20 is moved to the 'left in Fig. '7.- A cam element H6 is mounted on throttle control'linkage lever 28"'and is adapted to abut the lower end of the external leg of rod I24 to elevate the rod I04 when the lever 28'is moved to some predetermined position by movement of the pedal I6 towards a Elevation of rod I04 throttle closing position. in response to the camming action of element H6 necessitates that spring I I: be overcome and this is accomplished bythe aforementioned re turn of the accelerator pedal toward athrottl e closing position.

Figs. .8, Sand 10 illustrate another form of the invention in which a'member 05"is provided with. a reduced end portion having a shoulder" I adapted to project out of the switch housing. A fixed plate I22, having a leg I24;extending in a horizontal direction therefrom is secured to the housing of switch 42 by a pair of screws I26. A cooperating plate I28 is provided with aborizontally' extending leg I30 andslots I32 and l24 for the reception of screws I 25. The slots permit vertical movement of the plate I28. A spring I38 ispositioned between the exten-= sions I24 and I and urges the plate I28 down wardly. When the member 6t" is moved to the left in Fig. 10 by contact of extension 80 of throttle control lever 28 the downward movement of plate I28 is facilitated. The slot I34, previously mentioned, is sufilciently long to have the member 60 extend therethrough. When the shoulder I20 of member 60 moves to the left suiliciently so that it passes the plane ofplate I28; the plate I28 is urged by spring I35 to move downwardly behind the shoulder I20 and prevent a return movement of member 60" to the right to a switch opening position. The lever 28 is provided with a cam element I40 which is adapted to cooperate with a curved lower extremity I42 of the plate I28 to overcome spring I36 and elevate plate I28when the throttle control linkage returns to some predetermined position in response to movement of the pedal It towards a throttle. closing position. Elevation of plate I28 freesthe member for'movement to the right under the influence of spring I2 to effect an opening of switch 42.

Fig. 11 illustrates another form of the invention which is capable oi obtaining a similar result. In Fig. 11 a switch generally designated by the numeral 200 is mounted on a vehicle carburetor in a manner similar to that of the switch, 42, referred to above. In this form of the invention the conductor M is electrically connected to .a contact 202 which-is carried by,

but insulatedfrom, the housingof switch 200.

A support 204, carried by the switch housing has a movable contact 206 pivotallymounted thereon. A second pivotally mounted member 208 has one end thereof connected to contact 206 by a spring 210 so that an over center switch is provided. A plunger 2 I2, corresponding to member 60 of Fig. 2 is slidably mounted in a cylindrical bore 2M provided in the switch housing and opposed in movement to the left in Fig. 11 by a spring 2l6. Theplunger 212 has an extended portion 2l3 of reduced diameter mounted for movement in a cylindrical chamber H9 in the housing of switch 200 and an intermediate shoulder 22!. Movement of plunger 2l2 to the left in Fig. 11 by contact of extension 80 on throttle control lever 28, as in the Figs. 3, 5 and 8 forms of the invention, causes Portion 2l8 thereof to move member 208 which, through spring '2), moves contact 206 to an over center position in which it is in electrical contact with contact 202 and the line 4| is grounded through the switch housing and carburetor.

The upper limit control of the Fig. 11 form of the invention includes a plate 220, having an opening 222 therein through which the portion MB of plunger 212 extends and which is slidably mounted in a transverse opening 224 in the switch housing. The plate 220 is connected to a diaphragm 225 which has a chamber 228 thereabove connected to a source of Venturi vacuum in the carburetor. Upward movement of the diaphragm is opposed by a spring 230. Upward of plate 220 in response to a high Venturi vacuum above diaphragm 226, when a predetermined vehicle speed is exceeded, causes shoulder 22I to be obstructed by plate 220 as opening 222 therein is disaligned with bore 2l9.

A device is also provided for unlatching the over center switch contact 206 in response to high manifold vacuum which is obtained as an incident to a closed throttle condition. A diaphragm 240 has a chamber 242 provided thereabove which is connected to a source of manifold vacuum downstream of the throttle valve. Manifold 250 is. illustrated in Fig. 11 as connected by pipe 252 to chamber 242. A slidable element 244 is carried by diaphragm 240 and provided with an abutment 246 adapted to engage a leg 248 of. member 208 to rotate member 208 in response to a high manifold vacuum and through spring 2lfl to retract contact 206 to interrupt the circuit through switch 200.

I claim:

1. In a motor vehicle having an internal combustion engine provided with a carburetor having a throttle valve, throttle valve control linkage, a variable speed ratio transmission, a solenoid actuator adapted to effect a relatively slow speed drive of said transmission when energized and a faster speed drive when deenergized and an electrical circuit including said solenoid actuator; a switch having amovable element adapted to close said switch and energize said solenoid when moved to a predetermined position, means associated .with said throttle valve control linkage and adapt-ed to move said switch element to the predetermined switch closing position as an incident to movement of said linkage in a direction tending .to open said throttle valve. a second means operable to maintain said switchin its predetermined solenoid energizing position. after said linkage is retracted from its said predetermined position and additional means operable to release said switch from its solenoid energizing position in response to substantial movement;

of said throttle control linkage in a direction tending to close said throttle valve.

2. A control for an electrical circuit ofa motor vehicle having an internal combustion engine provided with a manifold and a carburetor having a throttle valve and linkage operable to control the position of said throttle valve; said controlincluding a switch having a housing, a first contact element, a second movable contact element and toggle means associated with said movable contact element and operable to retain the latter element in electrical contact with said first contact element, means to move said second contact element including a plunger slidably carried in said housing, spring means normally urging said plunger away from said second contact element, means associated with said linkage and operable to overcome said spring means and move said plunger and said second contact element to effect a closing of said switch as an incident to movement of said linkage beyond a predetermined position in the direction tending to open said throttle and manifold vacuum responsive means operable to overcome said toggle means and separate said contacts in response to a high engine manifold vacuum condition.

3. A control for an electrical circuit of a motor vehicle having an internal combustion engine provided with a manifold and a carburetor having a throttle valve and linkage operable to control the position of said throttle valve; said control including a switch having a housing, a first contact element, a second movable contact element and toggle means associated with said movable contact element and operable to retain the latter element in electrical contact with said first contact element, means to move said second contact element including a plunger slidably carried in said housing, spring means normally urging said plunger away from said second contact element, means associated with said linkage and operable to overcome said spring means and move said plunger and said second contact element to efiect a closing of said switch as an incident to movement of said linkage beyond a predeter mined position in the direction tending to open said throttle, a diaphragm having a mechanical connection with said toggle means and operable to separate said contacts when moved in a first direction and means subjecting one side of said diaphragm to engine manifold vacuum for movement in its first direction when a predetermined manifold vacuum is exceeded. 1

I 4. In a motor vehicle having an internal combustion engine provided with a carburetor having a throttle valve, throttle valve control linkage, a variable speed ratio transmission, a solenoid actuator adapted to effect a relatively slow speed drive of said transmission when energized and a faster speed drive when deenergized and an electrical circuit including said solenoid actuator; a switch having a plunger device slidably mounted for movement between a first position eifecting an electrical closing of said switch. and an energization of said solenoid and a second position effecting an electrical opening of said switch and deenergization of said solenoid, spring means urging said plunger device to its second position, means associated with said throttle valve control linkage and adapted to move said plunger device to its first position as an incident to movement of said. linkage in a direction tending to open said. throttle valve and beyond a first predetermined position, latching means operable to engage said plunger device and maintain said switch LOUIS B. FORMAN.

The fol 10 REFERENCES CITED lowing references are of record in the file of this patent:

Number UNITED STATES PATENTS Name Date Hutt Sept. 25, 1934 Number et a1 Aug. 31, 1943 Neracher et a1 Nov. 9, 1943 Webb Feb. 29, 1944 Boyce Mar. 12, 1946 

